SUBSURFACE DRIP IRRIGATION FOR BERMUDAGRASS WITH RECLAIMED WATER

Abstract

Subsurface drip irrigation was compared to sprinkler irrigation of bermudagrass turf in a multi-year experimentusing reclaimed water. The experimental plots were established with sprinkler irrigation. During the following three irrigationseasons, plots were irrigated when the average soil water content in the upper 30 cm of soil decreased below 20% byvolume, which corresponded to a management-allowed depletion value of 50%. The amount of irrigation water, the visualappearance of the turf, shoot biomass production, soil salinity, and health risks due to reclaimed water reuse were examined.Management problems such as emitter clogging were identified. No emitters were completely clogged, and emitter cloggingwas not serious enough to impact visual quality. Statistical uniformity of emitters was reduced from 91.8% (for new emitters)to 85.3% after the first year and 86.2% after the third year, while flow rates remained at 3.75, 3.78, and 3.89 L/h, respectively.The amount of water applied in the subsurface drip irrigated plots to maintain acceptable visual quality was similar to thatapplied in the sprinkler irrigated plots. Increases in the electrical conductivity of the soil surface of the subsurface drip irrigatedplots were noted after the first and second seasons. However, these increases were not high enough to negatively affectturf appearance. Inspection of the emitters at the end of the irrigation seasons found signs of root intrusion into the emitters,which may pose a threat to the long-term use of subsurface drip irrigation.